One promoter calls them: "debt reduction schemes". They're anything but. They create debt, often for the people who can least afford to get involved.

In the last few years, more than £3bn has changed hands through pyramid schemes.

They go under several guises such as Circles of Success or Heart schemes. But in principle, whatever shape or size, they're all the same.

You hand over several thousand pounds, and are told you will get maybe seven or eight times that amount back. So: £3,000 in, £24,000 back. Sounds great, but it isn't.

Matt Allwright and the Scambusters team have investigated complaints from people affected by these schemes all over the UK. Programme makers set out to get inside the schemes, to see how they work and expose the people behind them.

The process

According to the Department of Trade and Industry, these schemes are a scam. The Queen's Speech announced plans for new legislation to outlaw them.

Only a small number of people make any money. Eighty-eight percent of those who put money in, get nothing back.

It all starts with a meeting, and they can be arranged just about anywhere: people's homes, private rooms in libraries, big hotel conference rooms.

The bigger, more open meetings, employ security guards. One of the groups infiltrated by the Scambusters team carried out body searches before each meeting.

At no point during the meetings attended by researchers, were people informed of the risks of losing their money.

Instead, they were regaled with success stories. The organiser of one particular scheme boasted how he kept £21,000 in cash under his bed.

It's the people who are first into these schemes who make the money. And they are the leaders and organisers.

They sit at the top of the pyramid, and start receiving money as people begin investing, and their money is fed through to the top.

One successful investor claimed to do this four times in less than a year, receiving a total of £96,000.

But when it goes wrong, like it did in Llanelli, South Wales, it's a very different story.

Aftermath

Families are ripped apart and lifelong friendships shattered.

As people fell into debt, anger and desperation translated into criminal acts. People had their windows broken, their cars set alight.

One woman promoting a particular scheme was secretly filmed at a meeting for potential investors describing it as, "a debt reduction scheme". But it targeted people who could ill afford to part with £3,000.

She later admitted to making £72,000 from three schemes, but for most, it is actually more like a "debt creation scheme".

The same woman, like many of the other organisers, exhorts people not to talk to the media about the scheme, stating that all the negative comments in the press and on TV are fuelled by jealousy surrounding their success.

Once the Scambusters team pinpointed some people at the top of such schemes and set out to give them a taste of their own medicine, scamming them right back.

The leaders of one scheme were invited to a meeting which had been set up by the programme to entice investors in a new area.

After listening in on the presentation, one member of the team tipped £1,500 in pound coins onto the table as his "contribution".

At this point Matt Allwright joined in to confront them about how they were misleading investors.

As with most scamsters, they refused to concede that there was anything wrong with the pyramid scheme.

They wouldn't admit that unless you were at the top, most people would lose their hard-earned cash.

Schemes like this are operating in the UK right now. Don't be tempted. Don't lose out to these scamsters.

Scambusters was part of the Hey Big Spender! event day on Wednesday, 28 January 2004. As well as pyramid schemes, the programme investigated postal, internet and share dealing scams. It was broadcast on BBC One at 2000 GMT.